The longest and the shortest day of the year
The difference between the Northern Hemisphere and the Southern one
In 2019, the winter solstice in the Northern Hemisphere is on 22 December, at 04.19 GMT.
When is this in your local time? Use the GMT to Local Converter.
Time 'investigators' may want to check the exact moment of solstices and equinoxes throughout the years.
Many of us find our lives governed by the length of days and nights. We call the longest and shortest days of the year the summer and winter solstice respectively.
The word solstice comes from the Latin for midsummer, expressing the idea that the sun is stopped in its ascent of the sky. In English, solstice is also applied to the shortest day.
The length of day depends on the journey the Earth makes round the Sun and the fact that our planet's axis is tilted by almost 24 degrees. As illustrated in this excellent article on the Royal Museums Greenwich website, it is a one-year journey marked by the two solstice moments.
If you think of the Northern and the Southern Hemisphere as the two halves of a coin and the Equator as the diameter or the line dividing it, the solstice dates are the same, but the season is different. What is Winter Solstice in the Northern Hemisphere is the Summer Solstice in the Southern one and the other way round. Encyclopaedia Britannica has a comprehensive article on the topic of the solstice.
While in the tropics daylight has a variation of a couple of hours, in the UK the difference between midsummer and midwinter is nearly nine hours (sunrise to sunset). This means winter nights are very long.
Greenwich, London, is famous for the Prime Meridian, 0 degrees of longitude. But how are our lives affected by latitude? At 51º of latitude the longest night is about 16 hours long. Closer to the poles the midwinter night lasts for months.
What is the length of days and nights where you are? How does this impact your commmunication across time zones?
Try these tools:
Across the UK, there are several sites associated with the winter solstice moment. One of them is off the northestern coast of Scotland, an ancient place that the midwinter sun has been lighting up for thousands of years. Learn more here.